Microdontia is hypotrophied sizes of teeth. This condition may be the result of allelic mutations at  single gene locus. Alternatively, incompletely penetrant non-allelic genes may show a synergistic effect as expected for a multifactorial trait with interacting gene products. This and similar kindreds may allow identification of genes involved in growth.
Keywords: Microdontia; Synergistic effect; Allergic mutation.